I picked this blazer up for $30. Any ideas on what kind of shirt / tie combos will work? I plan on wearing it with navy or khaki chinos and brown shoes.

If you're wearing it with navy pants, I'd wear light colors. Maybe like a light blue oxford shirt and red tie, pink, a contrast blue, and yellow/orange would go too depending on the hue. That color of brown is a little hard because it's not plain khaki. I can wear pretty much anything with a lighter jacket.